1. Field of the Invention
The invention relates to a system for fluidly connecting and retaining a sensor to an intake manifold of an internal combustion engine.
2. Description of Related Art
Internal combustion engines have an intake manifold. The intake manifold can be formed of any of a number of materials, such as aluminum, but today are more commonly injection molded from a plastic or other composite material.
These composite materials have the advantage of light weight, low cost, and sufficient tensile strength for withstanding the normal loads imposed upon them. A disadvantage lies, however, in their ability to withstand the fine shearing forces created in bolting components directly to the composite, as in forming or tapping threads in the composite that must withstand bolt tightening torque. This weakness of composites has traditionally been overcome by the use of internally threaded metallic sleeves, press-fit into wells or apertures formed in the surface of the molded part. The attached components are then attached to the molded part with fasteners threaded into the metallic sleeves, or the component itself has external threads for mating with the sleeve.
These methods also have a percentage of failures as the press-fit sleeve sometimes breaks loose of the molded part, coming completely loose or at least causing a leak. In some applications, an attached component requiring a sealing connection with the molded part is attached to the manifold with fasteners on each side of the component. Uneven or sideways forces on the connectors can cause the seal between the attached component and the molded part to leak. So, while this method can overcome the weakness of the molded part in retaining attached components, it also introduces other failure modes. It also weighs against the advantage found in the lower weight, and, especially, the lower cost of the single injection molded part.
It would therefore be advantageous to develop an alternative method of attaching components to an injection molded part, such as an intake manifold. Such a method would take advantage of the flexibility of injection molding, and would avoid the requirement for additional fixtures for securely but removably attaching components to the injection molded part. This method would also avail a sealing attachment of such components to the molded part. This method would also be adaptable to a part formed or machined by a method other than injection molding.